WASHINGTON (AP) — President Donald Trump, lagging in the polls and grappling with deepening economic and public health crises, on Thursday floated the startling idea of delaying the Nov. 3 presidential election. The notion drew immediate pushback from Democrats and Republicans alike in a nation that has held itself up as a beacon to the world for its history of peaceful transfer of power.

Trump suggested the delay as he pushed unsubstantiated allegations that increased mail-in voting due to the coronavirus pandemic would result in fraud. But shifting Election Day is virtually impossible and the very idea represented another bracing attempt by Trump to undermine confidence in the American political system.

The date of the presidential election — the Tuesday after the first Monday in November in every fourth year — is enshrined in federal law and would require an act of Congress to change.

Top Republicans in Congress quickly rebuffed Trump’s suggestion. Senate Majority Leader Mitch McConnell said the election date is set in stone and House GOP leader Kevin McCarthy said the election “should go forward” as planned. Regardless, the Constitution makes no provisions for a delay in the end of Trump’s term — noon on Jan. 20, 2021.

“With Universal Mail-In Voting (not Absentee Voting, which is good), 2020 will be the most INACCURATE & FRAUDULENT Election in history,” Trump tweeted Thursday. “It will be a great embarrassment to the USA. Delay the Election until people can properly, securely and safely vote???”

In fact, only five states conduct elections entirely by mail, although more states expect to rely more heavily on mail-in ballots in November because of the virus outbreak. California has announced plans to send ballots to all registered voters for the fall election, but will also have in-person voting options available.

Trump’s tweet came just minutes after the government reported that the U.S. economy shrank at a dizzying 32.9% annual rate in the April-June quarter, by far the worst quarterly plunge ever, as the coronavirus outbreak shut down businesses, threw tens of millions out of work and sent unemployment surging to 14.7%.

With just over three months until Election Day, Trump trails in the polls nationally and across battleground states, and some surveys even suggest traditionally Republican-leaning states could be in play.